Radiographic inspection of tube welds in panel walls

Abstract

A method of inspecting tube welds in tubular membrane panel walls whereby a radiation source if placed intermediate adjacent tube welds with radiographic film positioned along the far wall of each adjacent tube thereby covering the far wall critical area of each tube weld. Simultaneously each radiographic film is exposed to an intermediate radiation source thereby creating an actual size image of each tube weld with both images totaling or equaling at least one full weld being radiographed per exposure.

What is claimed as invention is: 
     
       1. A radiographic method of inspecting tube welds in tubular membrane panel walls comprising the steps of: (a) installing a radiation source intermediate an adjacent pair of tube welds in a tubular membrane panel wall, said radiation source either being centrally positioned directly between said pair of tube welds or said radiation source being offset from said centrally positioned location;   (b) securing a radiation receiver around a perimeter portion of each said tube weld thereby closely conforming to the respective perimeter portion of said tube weld and also covering at least one critical area of said tube weld, a critical area of a tube weld being that region where a tube and a membrane bar join; and,   (c) simultaneously exposing said radiation receiver to said radiation source thereby creating an image of said perimeter portion of said tube welds.   
     
     
       2. A radiographic method of inspecting tube welds as set forth in claim 1 further comprising the step of using one or more sheets of radiographic film and affixing said sheet or sheets to cover the far wall critical area of said tube welds. 
     
     
       3. A radiographic method of inspecting tube welds as set forth in claim 2 further comprising the step of creating an approximately actual size image of each said tube weld. 
     
     
       4. A radiographic method of inspecting tube welds as set forth in claim 3 further comprising the initial step of removing a segment of said membrane bar intermediate said adjacent tube welds, said removed segment being sized to permit the installation of said radiation receiver around said perimeter portion of said tube weld. 
     
     
       5. A radiographic method of inspecting tube welds as set forth in claim 4 further comprising the step of securing said radiation receiver around at least half the circumference of its respective said tube weld. 
     
     
       6. A radiographic method of inspecting tube welds as et forth in claim 2 further comprising the step of offsetting the location of said radiation source to one side of the plane containing a said tube weld. 
     
     
       7. A radiographic method of inspecting tube welds as set forth in claim 2 further comprising the step of offsetting the location of said radiation source to one side of the plane of said tubular membrane panel wall. 
     
     
       8. A radiographic method of inspecting tube welds in tubular membrane panel walls comprising the steps of: (a) installing a radiation source in close proximity to an adjacent pair of tube welds in a tubular membrane panel wall, said radiation source either being centrally positioned between said pair of tube welds or said radiation source being offset from said centrally positioned location;   (b) securing a radiation receiver around a perimeter portion of each said tube weld, the maximum distance of said source to any region of said radiation receiver being no more than approximately 1 to 1 1/2 diameters of said tube weld; and,   (c) simultaneously exposing said radiation receiver to said radiation source thereby creating an image of said perimeter portion of said tube welds.   
     
     
       9. A radiographic method of inspecting tube welds as set forth in claim 8 further comprising the step of using one or more sheets of radiographic film and affixing said sheet or sheets to cover the far wall critical area of said tube welds. 
     
     
       10. A radiographic method of inspecting tube welds as set forth in claim 9 further comprising the step of creating an approximately actual size image of each said tube weld. 
     
     
       11. A radiographic method of inspecting tube welds as set forth in claim 10 further comprising the initial step of removing a segment of said membrane bar intermediate said adjacent tube welds, said removed segment being sized to permit the installation of said radiation receiver around said perimeter portion of said tube weld. 
     
     
       12. A radiographic method of inspecting tube welds as set forth in claim 11 further comprising the step of securing said radiation receiver around at least half the circumference of its respective said tube weld. 
     
     
       13. A radiographic method of inspecting tube welds as set forth in claim 9 further comprising the step of offsetting the location of said radiation source to one side of the plane containing a said tube weld. 
     
     
       14. A radiographic method of inspecting tube welds as set forth in claim 9 further comprising the step of offsetting the location of said radiation source to one side of the plane of said tubular membrane panel wall. 
     
     
       15. A method of inspecting tube welds in tubular membrane panel walls comprising the steps of: (a) installing a radiation source intermediate an adjacent pair of tube welds in a tubular membrane panel wall;   (b) positioning a radiation receiver on the distal or far wall side of each said tube weld with respect to said radiation source, said radiation receiver being in close proximity to its respective said tube weld; and,   (c) simultaneously exposing said radiation receiver to said radiation source thereby creating an image of said tube weld   
     
     
       16. A radiographic method of inspecting tube welds as set forth in claim 15 further comprising the step of using one or more sheets of radiographic film and affixing said sheet or sheets to cover the distal or far wall side of said tube welds. 
     
     
       17. A radiographic method of inspecting tube welds as set froth in claim 16 further comprising the step of vertically offsetting the location of said radiation source with respect to the horizontal plane containing a said tube weld. 
     
     
       18. A radiographic method of inspecting tube welds as set forth in claim 16 further comprising the step of horizontally offsetting the location of said radiation source with respect to the plane of said tubular membrane panel wall. 
     
     
       19. A radiographic method of inspecting tube welds as set forth in claim 16 wherein said radiation receiver is positioned tangent to its respective said distal side of said tube weld. 
     
     
       20. A radiographic method of inspecting tube welds as set forth in claim 19 wherein said radiation receiver is positioned tangent to the far wall critical area of its respective said tube weld, a critical area of a tube weld being that region where a tube and a membrane ar join.